In a bowl, whisk together the whole wheat flour, all purpose flour, baking soda, cinnamon, and salt.

In a large stand mixer, cream together the butter, apple sauce, sugar, and brown sugar. Add the eggs, one at a time, and mix. Add the milk, vanilla, and mashed bananas and mix. Add the dry ingredients into the wet ingredients and mix just until combined. Fold in the frozen blueberries. Use a ice cream scoop to evenly distribute batter to muffin liners, which will fill them 3/4 full.